Fiber dispersing and felting apparatus



July 25, 1967 w. J. oJA

FIBE DISPERSING AND FELTING APPARATUS Filed Jan. 13, 1964 Ina/vena( Maz/yn@ J' Oja United States Patent() 3,332,114 FIBER DISPERSING AND FELTING APPARATUS Wayne J. Oja, Cloquet, Minn., assignor to Wood Conversion Company, St. Paul, Minn., a corporation of Delaware Filed Jan. 13, 1964, Ser. N0. 337,361 1 Claim. (Cl. 19-156.3)

The present invention relates to dspersing fibrous material and -felting the dispersed fibers.

The apparatus is useful |for aggregates of vegetable fiber, and for mineral fibers which are commonly provided in nodules, which nodules contain shot-bearing fibers. For such nodules, the apparatus is provided with a construction which de-shots and denodulates the mineral fiber, and with a construction effectively removing the separated shot from the fibers which are delivered for felting.

In particular, the apparatus is arranged to discharge dispersed fibers in a stream of air in one direction, and to change the path of said fibers into an angular direction, preferably at about 90. This is necessary only when the fibrous material contains particles which are heavier and more compact than the fiber, such as the shot referred to, or which contains vegetable fiber bundles or slivers, in order that inertia of such particles in motion carries them beyond the region where the fibrous material is deflected by change in direction of a vehicular air stream.

A suitable apparatus is illustrated in the accompanyin-g drawing, in which the apparatus is illustrated more or less diagrammatically.

In the drawing, numeral designates a housing serving as a conduit, into which air is drawn at its opening 12, shown at the top of the housing, which is preferably vertical in extent. Bafiies 14 and 16 provide a hopper-like entrance at the top which opens above the nip of two brush rotors indicated by parallel cylindrical rolls 18 and 20. Each roll has a brush-forming multiplicity of bristles projecting radially, as indicated by numerals 22 and 24. The ends of the bristles of each rotor either just touch or overlap the path of the ends of the bristles of the other rotor during rotation of the two. The rotors are adjustable toward and away from each other in order to control the extent of overlap and also to compensate for wear. The extent of overlap may vary up to about SAG inch, when the rotors are about 12 inches in diameter.

Above the hopper formed by the baffle 14 and 16 there is provided means for feeding fibrous material to the rotors 18 :and 20, such as an endless conveyer belt 26 |for a supply of fibrous material 28. When other material or a. second kind of fiber also is to be included in the felt, another feeding means may be used, such as endless conveyer belt 30. Numeral 32 indicates a second material so fed into the hopper, such as a thermosetting resin powder which may be thermally activated in the felt to bind the fibers thereof.

When the material 28 is nodulated mineral wool, containing shot-Ibearing fibers, the rotors 18 and 20 may be operated and positioned so that nodules are refined or denodulated, and at the same time, shot is broken from the fibers and discharged with individualized fibers with a possi'ble content of incompletely denodulated nodules.

Experience has shown that best results are obtained by incompletely denodulating and de-shotting by rotors 18 and 20, and then continuing the action with a second set or rotors 18 and 20 which duplicate in structure and speed, but not necessarily in mutual adjustment, the first set of rotors 18 and 20. With two sets, a single drive means is provided for rotors 18 and 18', such as the driven gear indicated at 34, connected by chain 35 to the rotors. Chain 36 passes over adjustable idler gear 38, to permit adjustment of either one or both sets of rotors in ICC the housing. For rotors 20 and 20 a second driven gear 34 is provided with chain 36 and idler gear 38'.

- Rotors 18 and 18 are indicated for operation at slow speed, for example, 5 r.p.m., and rotors 20 and 20 for high speed, for example, 960 r.p.m. These relative speeds are not critical, since speeds of 1 and 3600 r.p.m. have been used and also 5 and 765 r.p.m. Where two sets of rotors are used the high speed rotors may Ibe slowed somewhat, -but must have a speed sufiicient in connection with the air stream through the housing to effect separation of non-feltable inertia material from feltable fibers.

Also, the detail of the brushes may be changed. When rotors 18 and 18 are 12 inches in outside diameter the bristles may be steel wire 0.0140 inch in diameter, and 3.25 inches long. When the rotors 20 and 20' are l2 inches in diameter the bristles may be steel wire 0.0118 inch in diameter and 2.75 inches long. The bristles are thickly concentrated on the core where they are mounted, both around the rotor and along the rotor, so that at the cylindrical periphery the free ends are ysubstantially uniformly distributed.

The material fed to enter the nip 40 of rotors 18-20 is fed to and held by the slow rotor 18 which slowly carries it into the nip. The fast rotor 20 combs fibers brought to it, and hurls material which may be fibers, shot and undefibered fibrous matter, tangentially Ifrom the exit end of nip 40 and toward the bottom of the housing. When the second set of rotors is present, the hurled material moves toward the nip 40 thereof. In order to prevent passage of material past the second set along the side walls of the housing 10, Ibaffles 14 and 16 are located to direct all the hurled material onto the Deripheries of the rotors 18 and 20 for passage through the nip thereof.

As a result, the one or two sets of rotors delivers a predominance of individualized fi'ber to be felted with a minor content of slugs, slivers, bundles, nodules or shot, as the case may be, which are not desired in the Ifelt to be formed.

To effect separation of such minor content from feltable fibers, a strong current of air is drawn into and through the housing and at a location above the bottom of the housing the air is drawn out of the housing at an angle, preferably to its direction in the housing. The lighter feltable fibers follow the vehicular air and the heavier material by its inertia of motion moves to the bottom of the housing and out of the air stream.

The arrow 42 indicates an air-suspension of feltable fibers leaving the housing 10 at lateral opening 44 in the housing above a closed bottom region 46. Arrow 47 indicates inertia material, such as shot, moving for collection at the bottom. In order to permit removal of the collected material, a rotary closing gate 48 is provided within a casing 49 from which the material 47 is discharged through outlet 49. The gate 48 has vanes which have rub-ber seals 48 as their tips. The vanes are foraminous with very small holes as indicated by the stippling in the cross-Section. This permits air to be drawn into the housing from conduit 49 to lift fugitive fibers which may have escaped the main stream.

Feltable fibers highly dispersed for felting tend to collect in fio-cs as they are conveyed in conduits, and especially as the conduits depart from a linear direction, and more so as the fibers tend to curl. In order to minimize exposure of the suspended fibers to such occulating conditions, the fibers are felted directly from the opening 44. This is effected by means which also provides the suction for drawing the air into and through the housing 10.

A suitable felting means has two endless wire screen belts 50 and 52 with planar stretches separated by a felting zone 54 tapering away from the opening 44. The

screen belts are backed outside the zone 54 by planar `banks of idler rolls 56 and 58 which banks are adjustable to vary the taper of the felting zone as required. Suitably disposed idler and driving rolls 60 and 62 are provided, respectively, for the ybelts 50 and 52, and are located so as to provide space for suction boxes 64 and 66 located at the entry end of the felting zone.

Suction boxes 64 and 66 are both connected by conduits 68 and 70 to the inlet of a suction fan 72, the operation of which draws air into the housing 10. The lateral extent of the suction boxes away from the housing is sufiicient to minimize the intake of air at the region 74, where the formed felt 76 is Sufiiciently dense. Beyond the region 74 the taper of the space 54 effects a compression of the felt or mat present at the region 74 to the density of discharge felt 78. The felt 78 so formed has sufiicient tensile strength to permit couching it from belt 50 to a conveyer belt 80 moving at the same speed as belts 50 and 52 over roll 82.

The mat 78 may be further treated in conventional ways, such as by further compressing it, or applying liners to it, or by applying heat to activate a binder such as the resin powder 32 referred to.

It is to be understood that the invention is not limited to the exact form of the apparatus illustrated to explain the nature of the invention, and that various uses and departures are contemplated as falling within the scope of the invention as expressed in the appended claim.

I claim:

Apparatus for dispersing liber and felting the dispersed liber to form a fiber felt comprising in combination a vertically elongated housing having vertical side walls and an open top end for the entry of air and material to be included in said fiber felt, means to feed material including fiber into said open end, fiber dispersing means in said housing comprising at least one set of two parallel cylindrical rotors inwardly from said open end, each rotor having a brush-forming multiplicity of bristles projecting radially from its roll, the ends of said bristles from each roll terminating in positions ywithin the peripheral path of the ends of the bristles of the other roll during rotation of the rotors, the entry end of the nip formed by said rotors facing said open end, motive means to rotate one of said rotors in a feeding direction into said nip at a relatively slow speed to serve as a rotary holder and feeder for fibrous material fed through said open top end to form a supply in said nip, motive means to rotate the other rotor in the opposite direction at a relatively greater speed to pick individual fibers from the supply in the nip and to deliver them tangentially in one direction from the exit end of said nip, two endless screen conveyers each having a first and second end, said conveyers being arranged in spaced facing relationship with their iirst ends spaced farther apart than their second ends to define therebetween a tapered felting zone, said conveyers having their said first ends adjacent to one side wall of said housing and their longitudinal axes extending at an angle to the vertical extent of said housing, a lateral opening in said one side wall of said housing positioned `between said first ends of said conveyers, a suction ybox for each of said conveyers located adjacent each of said first ends, suction means connected to said suction boxes for drawing air into and through the housing and through said conveyers, said housing having a bottom below said lateral opening, said bottom and said side walls between said bottom and said lateral opening defining a receptacle below said rotors, whereby the air drawn by said suction means into and through said housing and said conveyers will have material including fibers entrained therein by said rotors and the relatively lighter materials will -be moved laterally through said lateral opening in the side wall and into the tapered felting zone between said conveyers for disposition on said conveyers to form a felt in said zone while the relatively heavier material will fall generally vertically into said receptacle, and conveying means positioned to receive the felt formed in and discharged from the screen conveyers.

References Cited UNITED STATES PATENTS 54,375 5/1866 Leinweber 19-145 483,590 10/1892 Waibel 19-145.7 2,255,227 9/1941 Parsons 209-135 X 2,715,755 8/1955 Jones 19-156 2,897,548 8/1959 Barnett 19-145.5 2,991,499 7/1961 Holcomb 19-156.4 X

FOREIGN PATENTS 447,174 3/ 1948 Canada.

MERVIN STEIN, Primary Examiner.

DORSEY NEWTON, Examiner. 

